The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
The invention in a first aspect relates to a rollo assembly, comprising a rollo screen for cooperation with an opening, said rollo screen having opposed forward and rearward edges extending in a transversal direction and two opposed side edges extending in a longitudinal direction, a winding shaft which is rotatable for winding on or winding off the rollo screen at the rearward edge thereof for determining the amount in which the rollo screen covers said opening, which winding shaft is biased for winding on the rollo screen, an operating beam connected to the forward edge of the rollo screen and defining two opposite operating beam ends, and two guide members extending in said longitudinal direction and each defining a guide channel for guiding a respective one of the operating beam ends.
In such a rollo assembly the operating beam is driven for moving the rollo screen to a desired position (while winding the rollo screen on or off the winding shaft) for in a desired amount covering or freeing the opening. It is for example possible that such a movement of the operating beam is carried out manually by engaging a dedicated part of the operating beam (such as, for example, a central grip area thereof). In other embodiments the rollo assembly comprises drive means for driving the operating beam (in which case, for example, push and/or pull cables are provided extending in the guide members and at a first end engaging the operating beam ends and at a second end being driven by an electric motor).
When the rollo assembly is to be used with a large opening, specifically an opening having a large dimension in the longitudinal direction, the operating beam (with attached forward rollo screen edge) will have to travel over a large distance between the position in which the rollo screen fully frees the opening (rollo screen maximally wound on the winding shaft, fully open position) and the position in which the rollo screen fully covers the opening (rollo screen maximally wound off from the winding shaft, fully closed position). Given a defined driving speed for the operating beam (for example in the event of using drive means such as an electric motor) this travel requires a substantial amount of time.